The present invention relates generally to temperature sensing apparatuses and more particularly to a temperature sensing apparatus configured to measure the temperature of an Air Conditioning or refrigeration coil at a bend in the coil.
Manufacturers of air conditioners, chilled water units, and other refrigeration related products have a requirement to measure the temperature of fluids or gases as they flow through evaporator and condenser coils. Because the coils are surrounded by fins, it is desirable to measure temperature at the coil return bends. However, temperature sensing apparatuses to monitor refrigerant of coils use xe2x80x9cclip-onxe2x80x9d techniques to monitor the refrigerant of coils by attaching to straight copper tubes. These apparatuses comprise a clip and a thermal sensor wherein the sensor is held on to a straight section of tubing by the clip.
A problem with the present xe2x80x9cclip-onxe2x80x9d techniques is that they are not suitable for a return bend because the return bend has a one-hundred-eighty degree bend that prevents the clip from attaching firmly to the tubing. Another problem with the xe2x80x9cclip-onxe2x80x9d devices is that that they do not provide sufficient surface area contact to allow for good thermal coupling between the sensor and the bent tube.
Other sensing devices use a sensor in combination with metal straps instead of clips. For example, a strap is tightened onto the bend with a screw and nut or hose clamp. However, these devices are difficult to mount on the tube because of limited space between the return bends and end plates. Thus, a need exists for a temperature sensing apparatus configured to measure the measure the temperature of an Air Conditioning or refrigeration coil at a bend in the coil.
Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of instrumentalities and combinations particularly pointed out in the appended claims.
In view of the aforementioned needs, the invention contemplates a clip for a return bend temperature sensor comprising a mounting base, at least one resilient arm extending from the base, the arm having a countered section adapted to mount onto a curved section of a tube, and a mounting well within the base. Typically, the clip would be comprised of a thermally conductive metal, such as for example copper, beryllium copper, or brass. The outer surface of the arms may be covered with molded rubber or plastic, for example a thermoplastic polyamide resin, so that the arms will be flexible enough to be shaped with the same contour of the bent tube, yet hard enough to retain its molded shape.
In another embodiment there is contemplated a return bend temperature sensor comprising a mounting clip and a sensing element. The mounting clip comprising a mounting base with a pair of thermally conductive metallic resilient arms extending from the mounting base in a substantially perpendicular direction from the base. Each of the resilient arms having an opposing inner contoured section adapted to mount onto a curved section of tubing. The base further comprising a mounting well wherein the thermal sensing with a thermally conductive epoxy is in the mounting well.
In yet another embodiment there is contemplated a return bend temperature sensor comprising attachment mean for clipping onto a curved section of tubing, the attachment means having a mounting well, and sensing means fitted into the mounting well for sensing the temperature of the curved section of tubing.
In still yet another embodiment there is contemplated a return bend temperature sensor comprising a clip with a mounting base, two pairs of thermally conductive metallic resilient arms extending from the mounting base, and a mounting well, and a sensing element with a thermally conductive epoxy fitted into the mounting well. The first pair of thermally conductive metallic resilient arms extend from a first end of the mounting base in a substantially perpendicular direction from the base. Each arm having an inner opposing contoured section adapted to mount onto a curved section of tube, and having an outer coating of molded plastic. The second pair of thermally conductive metallic resilient arms extend from a second end of the mounting base in a substantially perpendicular direction from the base. Each arm having an inner opposing contoured section adapted to mount onto a curved section of tube, and having an outer coating of molded plastic. The return sensor is suitably adapted such that the sensor is in thermal contact with the clip, and the sensor and clip are in thermal contact with the curved section of tube thereon.
One aspect of the present invention is that the sensor has a fast response time. This is because the sensing element is embedded in into the thermally conductive clip with thermally conductive epoxy and because there is a significant amount of the clip in direct contact with the bent tube, thus the temperature is efficiently transferred to the sensor. Another aspect of the present invention is that the invention allows an installer or field technician to easily attach the sensor to a bend in a tube in just a few seconds.
Among those benefits and improvements that have been disclosed, other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.